1. Field of the Invention
The present invention relates to a cap opening and closing mechanism which is attached to a discharge port portion of a container.
2. Description of the Related Art
As a cap which is fitted to a discharge port of a container in which a seasoning such as salt or pepper is filled, there is a type which has a structure for opening and closing a lid by a so-called push-and-push mechanism in view of the ease of use.
As shown in FIGS. 14 to 18, in a cap 300 of this type, a button 304 which is adapted to be pushed is provided on a side surface of a hollow cylindrical cap body 303 attached to a container 302.
A slide lever 308 is connected to a reverse surface of the button 304 by means of a thin-walled hinge 306 in such a manner as to be swingable with respect to the button 304. This slide lever 308 is passed through a housing 310 disposed in such a manner as to traverse the discharge port of the container 302, and reaches a rotatably supporting portion of a lid 314 which is rotatably attached to the cap body 303 by means of a rotating shaft 312.
An elongated hole 316 is formed in the slide lever 308 along a longitudinal direction thereof. A pin 313 provided at one end of a link lever 318 is swingably inserted in the elongated hole 316, so that the link lever 318 is movable while swinging. Further, the link lever 318 is urged toward the rotatably supporting portion of the lid 314 by means of a spring 320 which is held by the slide lever 308.
Meanwhile, an engaging recessed portion 322 is provided at the other end of the link lever 318. In a state in which the lid 314 is closed, the engaging recessed portion 322 is slidably engaged with a receiving portion 324 which is provided on the rotatably supporting portion of the lid 314 and projects from a lower side of the rotating shaft 312 toward the button 304. In addition, pressing surfaces 326, 328, and 330 against which a distal end of the slide lever 308 abuts in steps are formed on the reverse surface of the lid 314.
In such a structure of the cap 300, as shown in FIG. 15, in the state in which the lid 314 is closed, the distal end of the slide lever 308 is opposed to the pressing surface 326. At this time, the link lever 318 presses the receiving portion 324 by the urging force of the spring 320. Accordingly, counterclockwise angular moment is produced about the rotating shaft 312. Consequently, the lid 314 is maintained in the closed state, so that the lid 314 cannot be opened inadvertently.
Next, if the button 304 is pushed, as shown in FIG. 16, the slide lever 308 first presses the pressing surface 328 and then presses the pressing surface 326 of the lid 314, thereby inclining the lid 314. Consequently, the receiving portion 324 rotates clockwise about the rotating shaft 312 such that a tip of the receiving portion 324 comes to be located at a position higher than that of the rotating shaft 312.
At this time, the link lever 318 moves along the elongated hole 316 against the urging force of the spring 320, and the engaging recessed portion 322 moves to a position higher than that of the distal end of the slide lever 308 while being guided by the receiving portion 324, thereby producing clockwise angular moment about the rotating shaft 312. As a result, even if the lid 314 is not completely opened by pushing the slide lever 308, the lid 314 is automatically opened to its completely open state.
Here, if the operator releases his or her finger from the button 304, as shown in FIG. 17, the slide lever 308 together with the button 304 moves in the direction of arrow A by the urging force of the spring 320, and the distal end of the slide lever 308 moves from the pressing surface 326 to the pressing surface 330 located below the rotating shaft 312. In addition, at this time, the link lever 318 presses the receiving portion 324, which has been moved to the position higher than the that of the rotating shaft 312, by the urging force of the spring 320, so that the lid 314 is maintained in the open state without rattling.
Next, if the button 304 is pushed, the slide lever 308 presses the pressing surface 330 located below the rotating shaft 312, so that counterclockwise angular moment is produced in the rotatably supporting portion of the lid 314, thereby closing the lid 314. A shown in FIG. 18, when the receiving portion 324 moves to the position below the rotating shaft 312 by the rotation of the lid 314, the link lever 318 pushes down the receiving portion 324 by the urging force of the spring 320, so that the lid 314 is automatically closed.
That is, in the structure of this cap, the closed or open state of the lid 314 can be maintained as the tip of the receiving portion 324 of the lid 314 which has been rotated about the rotating shaft 312 is pressed by the action of the link lever 318 supported rotatably and slidably by the slide lever 308. In addition, even if the lid 314 is not completely opened or closed by the slide lever 308, the lid 314 is automatically opened or closed from a predetermined position by the link lever 318 urged by the spring 320.
However, in commodities which are premised on mass production as in the case of caps of containers, it is required that the number of component parts be small and the structure be simple in the light of assembly and production cost.
In addition, since the slide lever 308 for imparting the pressing force from the button 304 to the rotatably supporting portion of the lid 314 traverses the discharge port of the container 302, a fixed limitation is imposed on a discharge rate at the discharge port.
Further, with the conventional cap 300, since the ability of the lid to hermetically seal the container 302 is low, if the container 302 containing a liquid topples over, there are cases where the liquid leaks from the gap.